1. Field of the Invention
Implementations of various technologies described herein generally relate to the field of geology and geophysics and more particularly, to the estimation of characteristics of formations containing salt bodies.
2. Description of the Related Art
The following descriptions and examples do not constitute an admission as prior art by virtue of their inclusion within this section.
Seismic exploration involves surveying subterranean geological formations for hydrocarbon deposits. A survey typically involves deploying acoustic source(s) and acoustic sensors at predetermined locations. The sources impart acoustic waves into the geological formations. The acoustic waves are sometime also referred to as “pressure waves” because of the way they propagate. Features of the geological formation reflect the pressure waves to the sensors. The sensors receive the reflected waves, which are detected, conditioned, and processed to generate seismic data. Analysis of the seismic data can then indicate the presence or absence of probable locations of hydrocarbon deposits.
Many subsurface-related human activities, such as oil and gas exploration and production, mining, underground construction, and earthquake prediction, can benefit from direct estimates of the state of stress of the earth subsurface. The importance of stress estimates increases when principal stresses are not equal to each other and when some preferred directions, e.g., directions of maximum and minimum stresses, exist in geological media.
Examples of applications requiring good knowledge of existing stressed state or pore fluid pressure include planning of drilling operation and mine construction. In those situations, poor estimates of effective stresses may lead to additional costs and safety problems related to geological hazards and instability of borehole or mine. Furthermore, the development of many existing oil fields and orientation of fractures are typically controlled by direction of maximum horizontal stress. Therefore, stress characterization performed prior to production may reduce risk in reservoir management decisions, particularly for production in areas having salt bodies.